Calculators were considered too expensive to be required or allowed on exams since only few college students could afford them at the time.

So it was still slide rules only for me until about 1974 when the entry level TI's dropped below $100 and became permitted.

Slide rule use dropped like a rock.

When I started, students calculating during exams were doing the same mathematical tasks using the same physical tools they had been doing in those halls since the 1920's, a few years later they started doing about the same things they have been doing electronically ever since.